Framebuffer is a display device inside Linux. How to operate the LCD at the bottom of the drive to achieve graphical display.1. What is Framebuffer?(1) First consider how we operate the LCD in bare metal.The SOC has an LCD controller, an LCD driver outside the SOC, an LCD driver connected to the LCD screen, a CPU inside the SOC, and an external DDR memory. These devices are all part of the LCD display.What
first, the Linux system divides the device into 3 categories: Character device, block device, network device. Using drivers:1, character device : Refers to a byte can only one byte read and write devices, can not randomly read the device memory of a certain data, read data need to follow the data. The character device is a stream-oriented device, and the common character devices are mouse, keyboard, serial port, console and led device.2, block device : Refers to the device can be read from any l
Transplantation of USB Wifi module RT3070 driver and wifirt3070 driver on the tianembedded E9 Platform
Due to project work requirements, point-to-point and multi-point transmission of wifi must be implemented on the embedded E9 platform.
Wifi module chip: Reiling 3070 Chip
Embedded platform: E9 (ARM)
Cross-compilation environment: arm-none-linux-gnueabi
1. First download the
1, create a device node in the/sys/class/directory, such as creating a CLASS_TEST_USB device node[CPP]View Plaincopy
Static struct CALSS *test_class;
Test_class = Class_creat (This_module,"Class_test_usb");
2, create another device node in the CLASS_TEST_USB directory android0, as follows[CPP]View Plaincopy
struct device *dev;
dev = device_creat (Test_calss,null,mkdev (0,0), NULL,"android0");
if (Is_err (dev))
return Ptr_err (dev);
3, create severa
The driver Microsoft Print to PDF required for the printer is unknown. Before logging on, please contact the Administrator to install the driver ., Microsoftprintpdf
After this problem occurred, I felt very confused because the printer was not installed on the server. Where did the printer come from?
Through Baidu search, I found a post on the Internet to answer my questions. Original post address: http:/
This is a creation in
Article, where the information may have evolved or changed.
Problem:2015/12/04 17:03:36 sqldb.go:2166:sqldriverconnect: {IM005} [MICROSOFT][ODBC Driver Manager] driver Sqlallochandle on SQL_ HANDLE_DBC failure
Environment: Go language writingSQL SERVER DatabasePackages used by the "CODE.GOOGLE.COM/P/ODBC" database operation
The program just started, running all right, but after a perio
I. Linux USB driver levels
1. devices, configurations, interfaces, and endpointsThe logical organization of a USB device consists of four layers: device, configuration, interface, and endpoint.
A device usually has one or more configurations:
Each USB device provides different levels of configuration information, which can contain one or more configurations, different Configurations enable devices to exhibit different combinations of functions (
Kernel:
Implementation Process of request_irq (riq, handle, irqflags, devname, devid );
Overall idea of Interrupt driver and Application Design:
Driver code implementation process:Third_drv.c
# Include
Application code implementation process:Thirddrvtest. c
#include
Access control is sometimes critical for the reliability of a device node. This part of content is only modified on the open and release methods, and some check mechanisms are added.
Exclusive Device
The most rigid access control method is to allow a device to be opened (exclusive) by a single process at a time, which is the simplest access control for a device driver. The implementation is very simple. For specific code, see the experiment source co
USB connection mode installation drive:
1, put the drive CD into the computer optical drive, and then open the disc, and then pop-up window we select "I have read and accept this License agreement", click Next, as shown in the following figure:
2, the following interface we selected "USB":
3, check the "software and utilities to install", and then click Next Action:
4, click "Advanced Options"-"Browse" This is to replace the driver installat
This article allows reprint, please specify the source:Http://blog.csdn.net/fulinusThe Linux kernel code is too big, a small module will let you unprepared, this afternoon resolved to take the SPI drive a good look.First analyze the spidev.c file, which defines the members in the struct file_operations structure. Members have Spidev_write, Spidev_read, and Spidev_ioctl, and the first two implement half-duplex communication, which implements full-duplex communication. Of course there are open and
ifeq (Some of them are common or we have seen, the first oneIfneq ($ (kernelrelease),)at present, it is useful to refer to the origin ofLinuxunder the source root directoryMakefilewhen compiling the kernel,Kernelreleasemacros are defined, so if you start from the source root directory Makeit will behello.oThe module is compiled into the kernel. KERNELDIR: =/ home/zp1015/desktop/linux-2.6.32.2 kerneldir Assignment, This variable is used to refer to the kernel source directory that we used l
What if the driver installation fails?
If you want to use 91 assistants to give you a mobile phone to install the driver, we have to open the phone's USB debug option to
here also to introduce another method: mobile phone installed 91 help
1, install a apk in the handset, then open the handset "WLAN" switch, simultaneously in the computer and the handset all runs "91 assistants".
2, then
A WiFi module was used in the recent project, the master being mt7612u, and the USB interface. Use of Linux version 2.6.35, in the process of compiling the driver encountered a lot of problems, especially in this record. Get the source
MTK official website Drive. Contains Windows, Linux, and drivers under the Mac. I modified the GitHub drive. Add a new platform
In the source code built some hardware platform configuration information, if not suitable
This question toss for a long, old thought is MySQL drive problem, fortunately finally found that El expression is not recognized${snapshot}"Problem:"-//sun Microsystems, INC.//DTD Web application 2.3//en""Http://java.sun.com/dtd/web-app_2_3.dtd" >The 2.3 version used by the servlet does not support El expressions by default, and the workaround is to add a sentence to the pageJSP page cannot use JSP cause MySQL driver cannot find "java.sql.SQLExceptio
Environment:
Operating system: 64-bit WIN7 database: SQL Server SP1 Development language: Java EE
Error prompting when Servlet connects to database:
[Microsoft] [ODBC Driver Manager] in the specified DSN, the architecture between the driver and the application does not match
Workaround:
Upgrade SQL Server SP SP1 to SQL Server # SP SP4 o
Now that we know the protocol, we can start to look at the SPI driver code in Linux kenerl. There are many struct in the code, so let's take a look at the main struct first, in this way, we can better understand the driver. Mainly include/Linux/SPI. h
The first is the communication interface between the SPI host and the slave, that is, the SPI bus,
extern struct bus_type spi_bus_type;
Bus_type is defined
, HDREADON3850 is a video card that is expected by a DIY player following Readon9550. "A rice n rice to pk!88gt and 3850 to see who more cost-effective" after the introduction of the new graphics card manufacturers must introduce a new driver with it. For ATI-driven comments, both praise and derogatory, can be regarded as mixed. is the ATI drive really so hard to tame? Not also, see the author how to train ATI graphics
[Microsoft] [ODBC driver manager] no data source name is found and default driver error information is not specified:
Source: Microsoft ole db Provider for ODBC Drivers
Description: [Microsoft] [ODBC driver manager] no data source name found and default driver not specified
Conn code:
function conn(){ try {
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